The Only Exception
by livingheaven
Summary: A long-awaited mistake could potentially ruin everything for the boys, but there might be a chance at resolution- if they can keep it a secret. Heronstairs. (Rated M for sex, tw: drugs)
1. Chapter 1

**A/N:**

 **Guess who's back, back again? Karma's back, tell a friend!**

 **So this idea has been stewing away in my mind pretty much ever since I started reading TDI, but I never really knew a way to go about it, until, of course, I had exams to study for and schoolwork to do and I needed to be actually productive instead of writing fanfic. So this is probably the longest thing I've actually written and completed- although the 'completed' has a question mark at the end of it, just in case you guys want more and I still need procrastination material. So, here we go! This chapter is very NSFW, so don't read if you're not into it, I've tagged the trigger warnings already so if you're triggered by any of that, definitely don't read.  
**

 **It's also sort of a songfic for "The Only Exception" by Paramore, so that might be good mood music for reading this. Okay, piece!**

 **xKarmax**

Will stood at the door of Jem's bedroom with a vibrant, widespread grin on his face. Jem was at the end of his bed, disentangling himself from his gear and laying his weapons out on the duvet. Will, himself, was still fully kitted up with Marks coating his arms like tattoo sleeves.

Once Jem had stripped himself down to his dull trousers and tunic, he turned towards the door to see a beaming Will, leaning against the door frame. He didn't seem to be looking at anything in particular; his eyes wandered in a space that only he knew. Still, he seemed to be happy there.

"Well, are you just staying for the show or would you like to step inside?" Jem asked, picking up a dagger from his assortment of deadly things and pulling out a casing from underneath the bed.

"You know I wouldn't miss a chance to bloat, dear parabatai," Will replied, taking a pronounced stride into the room.

"Oh dear, the parabatai is coming out," Jem said. "Should I protect my delicates?" He wrapped his arms around himself in a mock protective manner.

Will laughed and made his way over to Jem. He swung an arm around Jem's shoulder, eliciting a deep, well-meaned sigh from the white-haired boy.

"I do think I really outdone myself today," he said, making wild gestures with his free hand.

"You have? You're forgetting who slit the beast's throat!" Jem said, turning his head to meet Will's gaze. He grinned faintly, pursing his faded pink lips until they were barely visable.

"Ah, but 'twas I who rendered it lame!" Will exclaimed, pointing his index finger towards the ceiling in a dramatic gesture.

Jem laughed, buckling forward underneath Will's still-present grip. "You're feeling poetic tonight."

"I am," he said, looking at Jem with twinkling blue eyes. "I want to be one of those warriors who everyone just assumes has said a lot of brilliant things, so they make stuff up and put them on the sleeves of their novels."

"I know just what kind of novels you would grace with your potty mouth," Jem laughed, "and there isn't a grand thing about them!"

Will's mouth dropped open in mock shock. He brought his free hand- the other still placed firmly on Jem's other shoulder- to his chest, pretending to swoon. "James Carstairs! You foul boy!"

"I'm deadly afraid you might be rubbing off on me," he said. "Now let go of me before I try to go to bed on a pile of knives."

Will laughed briefly and let his hand fall by his side. He sidestepped away from Jem and leant over the bed, gathering a seraph blade and a mace in one hand. "Geez, you don't half prepare yourself," Will jested.

"Well, you never know what's out there- demon or mundane," Jem explained, his voice taking on an air of calmness rarely found outside monasteries.

"You're really afraid of mundanes?" Will asked from halfway across the room, kneeling on the carpet to set things away in drawers.

"Not afraid, as such," Jem replied. "Just vigilant."

When all of the sharp objects were cleared up, the two boys took a seat on the end of the bed. Will rested his elbow against the bed post and looked over at his white-haired parabatai.

"You know, we've really got to stop doing this," Will said with a mischievous grin on his face.

"And what would that be?" Jem asked, turning his head towards Will in a mock-dramatic fashion.

"Talking like this in the middle of the night," he explained. "There's a girl through there now." He whispered the word 'girl' as if Tessa could hear him.

"You're just embarrassed that she caught you," Jem said.

"Me? You were the one calling my name like an apathetic lover!"

Jem chuckled, one of those betraying laughs that fall from your mouth no matter how you try to stop it, and whacked Will playfully on the knee with the back of his hand.

"Ow!" Will groaned superficially. "You have to admit, though, you walked right into that one."

"Fine," Jem said with a faint, mirthful grin. The little colour that was left in his eyes sparkled. "I won't kill you today, then."

"You say that, but I'm the one wrapped up in knives," he said, gesturing to his weapons belt.

"Why do you still have that on, anyways?" Jem asked. "It's not like I'm going to be engaging you in combat any time soon."

"No, I think our sparing session yesterday more than tired you out." He winked and stood up, reaching down to his midsection to disentangle the belt. Without missing a beat, Jem got up with him.

"Let me do it," Jem said softly, stepping forward before Will had a chance to protest. His hands found their way to Will's hips after a few accidental brushes against his hard stomach. "I wouldn't want you to get hurt by your own weapons." He caught the belt between his middle and index finger, pulling it back with his middle until his knuckle was lightly pressing against the waistband of Will's trousers.

"Jem, I am a big boy who can operate a weapons belt himself. Besides, everything's in its sheath." Despite his protests, Will made no stretch of effort to pull Jem's hand away.

"Well, how am I to know you didn't accidentally leave something unsheathed?" Jem asked, meeting Will's gaze as his hands went to work unbuckling the belt. "We can't have our brave, poetic warrior wounded, now can we? It'd be a shame for all those novel-writers."

The corner of Will's mouth turned up. He tilted his head microscopically, trying to find answers in Jem's deep grey eyes. Jem quirked an eyebrow as he looked over Will, noting every little change and spasm as he let the belt drop to the ground with a subdued clank.

"You know, that's probably a health risk," Will poked, breaking away from Jem's captivating stare for a moment to observe the fallen belt.

As if by reflex, Jem extended a long, piano player's finger under Will's chin and gently tilted his head upwards. All of a sudden, Will was all too aware of the closed distance between them and the fact that Jem's chest was inches away from his.

"Why? Everything's sheathed, anyways."

Slowly but surely, Jem leaned in. Their lips met halfway after what felt like an age in Will's mind, and somehow they fit together perfectly. Every little motion, every little advance where just a little more assertiveness drizzled into the kiss ebbed and flowed naturally, like their lips were opposing currents and Will's grip on the bed post behind him was the only thing keeping him anchored. The only thing keeping him from melting.

Without quite following one action to the next, Jem found his hands tangled in Will's hair and his body slowly turning towards the bed. Will's free hand rested firmly on Jem's back, but the room was spinning far too much to tell whether he was being guided or moving by his own free will. His back hit the duvet with an almighty creak, although Will's scent muddled his head up far too much to be roused by a noise. In the next instance where he could collect his thoughts, Will was looking down on him, a hand on each shoulder. His deep blue eyes shone out against the witchlight, and Jem's breath hitched. Of all the things he could get worked up about- Will's rock-hard chest just inches from his, his hot breath warming Jem's throat- his mind went straight to fawning over how beautiful Will's eyes were. Typical.

Still, Will worked differently. His fingers trailed down Jem's tunic, keeping his eyes locked with Jem's as if to say, 'Up here.' A sly grin came across his face as he found the hem of the tunic and slowly, teasingly, peeled it up over Jem's head.

"Nasty pieces of work, those," Will cooed softly, "always getting in the way."

Jem took a deep breath, his body trembling ever so slightly as he let it out. It was getting to him- the look in Will's eyes, his body so close.

Please. Now.

As if Will's probing eyes could read his mind, he took his hands from Jem's shoulders and wrapped them around the nape of his neck, allowing himself to fall with only Jem's body as a cushion. He crashed happily into Jem's lips, setting Jem's skin alight. His hand frantically searched for steady ground, for something to hold onto but it seemed that no matter what he found, he could never shake the feeling of being so wrapped up in Will that nothing felt solid. Nothing but Will's lips on his and Will's heartbeat thumping into his own chest. His hands eventually found purchase on Will's back, fervently tracing the lining of his spine up and down, up and down.

Will wormed his arms into the space between Jem's back and the duvet, gripping onto his sides. From there, he flipped Jem sideways so that they were lying next to each other. Jem was too lost in Will's body to even notice the change, but it became more obvious when Will closed what little distance there was between them and started to snake his legs around Jem's. Jem's mouth popped open, but Will just used to opportunity to kiss harder and deeper.

An intense, heavenly sensation slowly creeped into his midsection. He moaned softly, but it was heavily muffled by Will's lips. Jem found himself scrabbling to intertwine deeper with Will; he wanted more. Will pulled back a little, letting out a slow moan directed at the ceiling. Jem used the short break in the kiss to press his lips against Will's ear and whisper, "Don't let them hear us."

Will smiled crookedly, and pulled Jem's lips back to his own without a reply. He masterfully twisted and turned his legs around Jem's dick, making it harder and harder for Jem to follow his own words. Jem tried his best to emulate Will's movements, but there was something distinguished about Will's manoeuvers, something unmistakably learned from experience. How many times had Will done this before?

Will began to thrust through Jem's legs, bringing his own body even closer and putting more sweet pressure on Jem's cock. Jem gasped out of pure shock at the sensation, and then a deep moan escaped him. Will's breath became increasingly erratic and heavy, turning into full-blown pants and rolled-back eyes. Jem bit his lip so hard that some colour went into it for once. It still wasn't enough to completely subdue his moans; a little voice, getting quieter by the minute as sensation overwhelmed him, was absolutely certain that somebody would have heard by now. How would they even begin to explain what was going on?

That voice was completely obliterated as Jem reached the brink. He could tell that Will was close too, by the way that his moans suddenly became hitched and breathless, as if each shockwave of pleasure rendered him unable to make a coherent noise. Every moment stretched out, doubled in time as he climbed higher and higher. Suddenly, his body was wrecked with a distinct feeling of adrenaline. It felt so alien to him; his best friend moaning in his ear, their bodies intertwined in a mess of limbs and sweat. Little embers of sensation trailed all the way around his body, back to his core, and euphoria coated every inch of his mind.

As he came, the room around him grew brighter and ecstasy infiltrated his mind, travelling down his back and setting his spine alight. A voice in the back of his mind that he hadn't even recognised yet screamed, "THIS IS IT. THIS IS EVERYTHING YOU WANT." He was powerless to stop it from continuing, from telling him that this was what love felt like, and he didn't care either way. There was nothing in the world he cared about right now except from Will Herondale.

The fire powering his body soon made its way to his tailbone, and began to settle around his midsection.

He became increasingly aware of a growing wetness- not just in his trousers, but pressed against him as well. Will's slow, soft, harmonious pants filled his ears. The black-haired boy's eyes were closed, and he was resting against Jem's pillow. As he came down from his post-orgasmic high, he looked serene, like he'd just came from an hour long meditation session and not gay sex with his best friend. His breathing steadied and he just looked as if he was sleeping.

Jem nudged him timidly. "…W…Will?"

Will grinned sleepily. "Go get changed, you're awfully uncomfortable to lie in."


	2. Chapter 2

Jem's eyes slowly fluttered open. For once, his eyelids were devoid of sleep and his head was, for the most part, clear. He'd fallen asleep sprawled diagonally across the bed, however now his head met a soft pillow instead of a hard chest. Jem grinned to himself.

"Jem?"

Tessa's quiet, soft voice at the door threw Jem from his memories.

"Oh, Tessa!" he said gleefully with a thin but vibrant smile. He sat up, wrapping his duvet around the nightgown he'd changed into from his gear. "How was your sleep?"

"Quite eventful, if I'm honest!" Tessa said, drifting into the room. She wore a long, white nightdress that made her look like something heavenly. Her long, untamed brown curls fell gracefully over her shoulders. Even having just gotten out of bed, she was so beautiful. It was almost maddening. "I had the most peculiar dream last night."

"Oh?" Jem asked, with an inquisitive sparkle in his eye. "I'd love to hear all about it, if you'd like."

"Oh, I can barely make sense of it myself," she said, floating ever nearer to the bed. "You were in it, and so was Will. Will was crying out, dreadfully- I got overcome by this sense that he was stuck, or had some sort of awful wound, but when I looked over my shoulder, he was walking alongside us quite the thing." She took a seat on the edge of Jem's bed, craning her neck to look at him. "I wonder, what do Shadowhunters think of dreams? Any idea of what purpose they serve?"

"Well," Jem said. He took a short pause, staring at his quilt thoughtfully, before looking up to meet Tessa's gaze. "Sometimes dreams can be given to individuals- that is, divine entities make them dream about certain things- but I don't think we need a creature of Heaven- or Hell, for that matter- to tell us that Will is a drama queen."

Tessa giggled into the cuff of her nightdress. "Oh, I suppose you're right," she said on the air of the laugh. "Charlotte and Henry wanted me to let you know that breakfast will be ready in about twenty minutes."

"Ah," Jem said, smiling pleasantly. "Let them know that I'll be down in just a moment."

Tessa nodded. "I'll leave you to wake up, then," she said, slowly standing up. She turned her body so that she was still facing the bed. "Do tell Will, if you see him, though, that-" There was a sudden, gentle clatter of metal slapping against metal. "-Oh, there's something on the floor here. Is that a weapon's belt?"

Jem pursed his lips together until they disappeared, his back shooting bolt upright. He tried frantically to shift the shock from his eyes. For some reason, having another person examine the evidence made last night far too real, and far too overwhelming to think about.

"Er- yes," Jem said, managing to steady his voice, "I was so tired when coming back from patrol last night, I must have left it on the floor!" He chuckled sheepishly, forcing his eyes to sparkle. "It's just a good thing you pointed that out."

Tessa's gaze floated slowly back and forth from the belt to Jem. Every time her eyes met Jem's, she seemed to have had another shocking internal revelation. "Well…you ought to be more careful with those things. I could have hurt my toe." Her tone was subdued and focused, as if she were trying to speak while balancing a ball on her head.

"Oh, you don't have to worry about that," Jem said, painting a wide grin on his face. "Everything's in its sheath, anyways."

She finally stilled her gaze on Jem. "Oh…that's not so bad, then. I'll…I'll see you at breakfast."

"Looking forward to it."

Tessa smiled dismissively and turned towards the door. Once she had left, Jem let out a relieved sigh, so loud that he immediately feared she'd pick it up. How could Will have been so careless?

…How could he have been so careless?

As he dressed himself, he dreamed up a scenario and ran over it until it was ingrained in his head; it was all he could do to take his mind off his chillingly fresh memories. He imagined going downstairs, taking Will aside- talking to him in private where nobody could possibly hear them. Explaining to him that last night was a fluke- was a mistake, and meant nothing. And that was where the picture froze, and something heavy and groggy ripped through his chest.

It had to mean nothing

It did mean nothing.

Right?

Jem shook his head, letting his eyes flutter closed for a moment. In his head, he spoke to himself the way he would a young boy.

No matter what you feel, it's wrong.

It's against the rules.

This isn't going to happen.

He let out a long, frustrated sigh and let his face fall onto his hands. Whatever he did, he couldn't let this consume his mind.

Nothing had happened yet. The world hadn't caved in, the wrath of an angry God hadn't smited them and everyone they loved- no matter what the mundanes standing on street corners with a bible would shout. That had to count for something.

He wrestled with his own head for a good few minutes before he managed to tuck this whole situation into a deep crevice in the back of his mind. Hopefully it would stay there until at least after breakfast, where it would undoubtedly rear its ugly head.

He made his way down the stone corridors of the Institute. Witchlight was more akin to sunlight than candlelight, so the walk there was reasonably cheerful. It would have been even more pleasant if the air around him didn't feel like lead, weighing down on him.

As Jem entered the dining hall, he squinted against the light pouring in from outside through the long window. Witchlight may be similar to sunlight in colour and feel, but it certainly didn't burn through the eyes like sunlight did. Aside himself, Jem wondered if that was why Jonathan chose the name 'Shadowhunter'.

Centred near the middle of the dining table was Henry and Charlotte Branwell, facing opposite each other and chattering away with faint smiles on their faces. Jessamine Lovelace sat down from Charlotte, scowling at her plate and absent-mindedly dragging her fork around her plate. Tessa sat opposite, in a fetching dark green dress. But, as far as Jem could see, the rest of the table was empty.

"Oh, good morning Jem!" Charlotte greeted as he approached the populous section of the table. She sat up from her plate and flashed Jem a toothy smile.

"Good morning, Charlotte!" Jem replied, pulling out a chair. "I don't suppose you've seen Will?"

"Ah…" Her smile slowly faded. "That is actually something I need to speak about, thanks for reminding me."

"Wait, what?"

"Have a seat, Jem," she said, gesturing towards the chair that he had pulled out.

Jem did so without another word, but kept his curious eyes trained on Charlotte.

"Will…wasn't in his room when we checked this morning," she explained.

Jessamine scoffed. "When is he in his room?"

"Jess…" Charlotte sighed. "This could be serious."

"It won't be, dear," Henry piped up. "You know the boy. He goes on…unexpected adventures all the time. I'm sure he's kitted himself up."

"He has his weapon's belt, at least," Charlotte admitted. "I'm just saying that everyone should keep a good eye out, and let us know if they've seen anything. Who saw him last?"

"Er…me, I think," Jem said sheepishly, staring at his plate. "We were on patrol last night."

"You were, weren't you? What did he seem like?" Charlotte set her cutlery down on the plate. "Where did he go?"

"He seemed…well, rather like Will," Jem explained, shrugging microscopically. "He helped me put my weapons away, and then he headed off. There wasn't much to it, really."

"Oh," Charlotte said, running the tip of her index finger along her chin. She studied Jem as he shifted uncomfortably in his seat. "That's…okay. It's good that he wasn't upset. Still…it does seem quite suspicious."

"Suspicious?" Jem's head jolted up. "How so?"

Charlotte's eyes widened just a little. "Well- I mean, just that if he didn't seem to have any reason to leave, there could be foul play involved."

"Now, let's not jump to conclusions," Henry said, setting his cutlery down and putting his hands out on front of him, as if to say, 'Stop'. "Give it some time. He'll be back. Trust me."

"Alright…" Charlotte said, turning away from Henry. She stared out the window thoughtfully. "But if he's not back here by tonight, we're taking action."

Henry's face was struck with a mixture of anxiety, fear and concern, but he just sighed and returned to his breakfast.

The rest of the meal was eaten in silence, save for a few malicious quips from Jessamine about Will's behaviour and a few sympathetic scoldings by Charlotte. All in all, the room felt dead without the black-haired rogue. It would have been worrying that nobody except for Jem and Charlotte seemed to be worried about Will's welfare, if Will wasn't so damn predictable.

As Jem finished off the last few bits of mash on his plate, he hoped to every God that Will wasn't as predictable as he thought.

"If you don't mind, I need to head out for an hour or two. I have some errands to run."

The east side of Limehouse was eerily quiet for a morning. The very fact that Jem knew what Limehouse was like usually, and could notice differences, was a testament to the rat hole that Will had dragged him into. He was slowly stepping off the road of civilisation and into the infested pit, otherwise known as Narrow Street. Jem couldn't count the number of times he'd been down here with Will, busting illegal merchants and human sacrifice ceremonies. They'd also been called out here many times before hunting demons. It was almost as if demons were attracted to the misery, the depravity and the desperation that seemed to flow through the air around here. But that didn't make much sense, since there was nothing here to destroy. There was nothing here to ruin; it was already a ghost town with a population of drug addicts, bastard children and whores. Maybe demons just came here because they liked the company.

It was, however, visits of a very different kind that led Jem to the front door of a certain house near the bottom of the street, in the middle of a straight road running past the house. The sickly lime green sidings were peeling off, almost blending into the forest of mould snaking along the outer walls. There was only one window upstairs that hadn't been smashed in, and even it had turned a peculiar yellowy colour. The house itself was just one of many treacherous- but far too familiar- abodes within close vicinity, but it was a start.

Jem raised his knuckle to rap on the door, but before he could, it was promptly opened and a horde of red-skinned creatures with talons for hands spilled out of the hallway and onto the street.

"What do you want, fen boy?" a woman asked from inside the house. She was leaning against the wall near the doorway, in front of a rickety staircase from where a soft, canine-like moaning could be heard. "Your degenerate friend was here only a few days ago. Surely you've not overdone yourself?" A small, sadistic smirk came across her face for a few moments, but then quickly faded. She pushed herself off the wall, squaring up to him. "Or have you come on more…official business? Hm?"

"I'm not here for the Clave." He gave his best effort to make his voice firm, but it still managed to trail off near the end. "I'm looking…for a friend. You know who I'm talking about."

Her mouth dropped open and curled, showing teeth that were a cross between cat's teeth and vampire fangs. "Word is that your certain…friend spends a lot of time around here." She began to slowly circle around Jem. "Not here, of course, but around…what makes you think he'd be here, of all places?"

"That's none of your business."

"Now, now," she said, standing on front of Jem, her teeth poised like a feline ready to pounce. "You can't be so touchy. Not around here, anyways. They'll eat you for breakfast."

"I assure you, I know what I'm doing," Jem maintained. "I came to find my friend. That's it. I will leave as soon as I find him."

The sultry glimmer faded from her deep red eyes, replaced with a hefty dose of contempt.

"He's not here," she said tersely. "He wasn't. Ever. If that's all you're here for, you can fuck off."

She pointed firmly to the door. Jem let out a deep breath, gave her one last indignant glance, and headed towards the open door.

"Just remember who controls your life support, Nephilim."

Jem kept walking until he was sure that he was out of her sight, and then stopped on a street corner a little up-road. Before he could deal with anything else, relief overcame him. He never truly expected that Will would do something like that- not again, at least- but Will was a creature of his own culture. Most of all, his visit was to clear his own head. He knew that Will was being tempted, getting offers. Up until now, Will's activities here had been nothing but harmless debauchery- a couple of times, Jem would find him in a brothel somewhere, in a seedy bar chatting up a warlock. He never seemed to really be doing anything with the women in the brothels, or the women in the bar, except for talking at an acceptable distance. But Jem knew that was just the tip of the iceberg, that there was so much that he didn't see.

He didn't really mind it; Will would be Will, and he knew there was something deeper underneath that. The same something that held him like he was scared he would slip through his fingers, that kissed him like he was all he could ever need. Even the thought made Jem's face screw up, made a small groan fall from his mouth.

Why?

Why this?

Why did they have to be parabatai? Why did they have to be forbidden? Why did they have to life this life at all? And, for the love of the Angel, why-

"…Jem?"

Jem's heart reached for his throat, slamming against his ribcage. It couldn't be.

"Jem, what are you doing here?"

Jem slowly lifted his head up, meeting two deep blue eyes, lighting up the entire forsaken place.

"Will!" Jem jumped towards him, throwing his arms around his parabatai. Will's body tensed up, stiffening like a board, until Jem stepped back.

"S-sorry…I just, I was worried about you."

"You shouldn't have been." His eyes were cold, dead. "I can look after myself."

"I needed to talk to you."

"What if I didn't want to talk to you?" He tried to keep up appearances, but his voice squeaked at the end of the last word and there was a drip of water forming in the corner of his eye.

"…Will…"

Will brought a hand up to his face, suddenly slipping down to the pavement. As if by reflex, Jem joined him.

"I meant it. Why did you even come here?"

"I told you. I was worried about you. I was worried that…that recent events might have…well, made you rethink some things."

"Oh, I'm rethinking everything." Will's head jerked up, meeting Jem's gaze with the deadliest glare he'd ever seen. "I'm rethinking this whole damned thing. I saw you at the ifrit house- I don't blame you. I almost went there."

"You did? Will!"

"-Let me finish. I almost did. It was a shaky almost. An almost-maybe-almost. I don't know why. Maybe I just wanted to spite you- I'm good at that."

The colour drained out of Jem's face. You don't mean that. You can't mean that.

"I wasn't going to do anything like last time. You have to believe me. I wanted to blow my mind to smithereens- yin fen just energises you. I didn't want to have energy, I wanted to sleep. Forever. There would have been no point. Trust me."

Jem couldn't help feeling a little reassured and a little relieved. It was becoming hard to stay on track, to continue his fuming rage uninterrupted.

"…But I couldn't even do that. All I could think about was the last time I was here. What I did to you. I couldn't fucking stand that again- I knew that would kill me more than drugs ever could."

"Well, I appreciate the notion!" Jem said, his voice laced with venom.

"No- you don't understand. I couldn't get you out of my head. You were the only thing I thought about. You were the only one I cared about. It…it scares me."

"So, what, you hadn't cared about me before? Your blood brother, your best friend?"

"Of course I had!" Will said, turning his body to face Jem's. "I care about you. So much. I worry about you all time. Of course I do. But it wasn't like that."

"Well, spit it out," Jem snapped. "What was it like?"

"It was like…it was like I was a galaxy, travelling aimlessly in space with nothing to follow, nothing to orbit or fall in line with. Free, independent. Without a care in the world except for the ones crammed into my head long before. But then, all of a sudden…my universe filled up. My planets fell into orbit, found a central point…and you, you became central to it all. You became the only thing I cared to protect. It destroyed me- suddenly I had all this responsibility and duty, and the only, single lone thought that went through my head was, "What would he want me to do?"

It's…ugh. I'm so fucking pathetic. Fucking look at me. I'm sitting at the side of the road in a poisonous town, proclaiming my stupid fucking love to my parabatai. I just…fuck."

The last word descended into a growl of frustrating as he threw his head into his knees.

"…You didn't say anything about love."

"What?" Will mumbled into his legs.

"You talked about solar systems but you never said anything about love."

Will abruptly pulled himself back up, glaring at Jem with a psychotic glimmer to his eyes.

"Do I have to fucking spell it out for you? I love you. I always fucking did. You're the one thing I allowed myself, the one exception, and I fucked it up. I fucked it up so badly." He aggressively wiped his sleeve over his eyes, throwing stars into his vision. "So I didn't go to the den. I also didn't go home. I knew you wouldn't want to see me. So I spent the night drinking." His voice softened, the fuse burning itself out.

"…Of course I wanted to see you," Jem said quietly.

"What?"

"Will. I left the Institute- alone- without telling anybody what I was doing, just to come here looking for you, because I wanted to keep this between you and I," he said. "What part of that screams, 'stay away from me'?"

Will let out a large puff of air that he had apparently been holding. "I don't know. I'm bad at mind-reading. I only ever thought you'd made a mistake."

"I did make a mistake," Jem said, tilting his head forward. "So did you. And we're going to have to live with that mistake. We just get to choose how we live with it."

"Well…" Will faced forward, and for the first time that day, a small smirk came over his face. If Jem listened really closely, he could have sworn he heard a chuckle. "You know I've never been one to pick the easy route."

Jem smiled, letting his eyes rest for a moment. When he opened them again, two deep blue eyes were staring at him intently, with a sly, half-grin.

"Here's to being difficult."

Will cupped Jem's face and brought him towards him. Their lips met in an easy, chaste kiss. Then they collapsed against each other, relief bringing fits of laughter out in them.

"We better get home. We'll work this out when we get there," Jem said, pressing his nose to Will's neck.

No matter how deeply he inhaled, Jem couldn't smell a whiff of alcohol on him.


	3. Chapter 3

Will and Jem trailed the dusty footpaths of Hyde Park, kicking through dirt shaken loose by an unexpected spell of hot weather. As ever, the park was overwhelmed with people; families playing in the sun, horsedrawn carts and carriages ambling their way through the greenery. They walked until large, imposing trees blocked the sunlight and found a wooden bench in a quiet corner of the park. It was entirely for their benefit; as usual, their Glamours kept them hidden from the day-walkers. It was always just easier to find peace when using Glamours, lest an unsuspecting bystander accidentally bump into them and then spend the next few minutes indignantly poking the "air" to see what on earth they just collided with. Or, worse, sit on them.

But today of all days seemed to require an exceptionally clear mind, exempt from distractions. From Limehouse, they made their way down to the city centre and spent a good while window shopping. Will got a replacement for a knee brace that he'd cracked- the blacksmith was a particularly amiable man who Will seemed to be quite friendly with, somehow, and so offered him the replacement for pennies. After that, they had a few rounds of aimless window shopping before they realised that nobody had said anything important yet. And so, they made a conscious decision to come here to discuss the matter at hand. As it happened, they were no good with planned discussions.

Will's head rested on his palm as he stared at the tree across from him. Oak, he figured. Chipped away, a little- he wondered who did that. Maybe nobody did. Maybe it was just a product of time. Interesting pattern.

"Will, are you just going to keep staring into space this whole time?" Jem asked.

Will straightened his back and turned his head to Jem. "Excuse me," he said defensively, bringing a hand to his chest. "I was doing some deep contemplation."

Jem despised himself for grinning a little at that. "Well, what's the result of your contemplation?"

Will fell silent. "…Trees really don't fare well in populated areas." He faced forward again. "I think we ought to live separately, every man…or, tree…for himself."

"I think we would die long before the trees if that were the case," Jem pointed out. "They only make the air we breathe."

"Well, yes, but maybe that's only fair!" Will leaned back, reaching an arm out to make an expressive gesture over the back of the bench. "We can't keep being freeloaders. I'm sure the trees are damn sick of our presence by now."

Jem laughed heavily. "Will, you're stalling."

"Can't a man just have some concern for his fellow…er…life…you know what, never mind," he said, turning his body towards Jem so that his legs were almost propped up in the space between them. "Stalling over. What were we talking about again?"

"Literally just a few hours ago. The situation."

"Ah, right, situation…" Will looked forward once again and tapped his chin, apparently in deep thought. After a few moments of silence, he looked up at Jem and said, "I got nothing. Your turn."

Jem laughed, although rather mirthlessly. Will's sense of humour seemed to balloon in bad situations; Jem's shrivelled, like a scared mole or some other like small earth creature.

"How about we start small?" Jem asked. "Take it in steps."

"Good idea. See, this is why you're the ones with the ideas and I'm the one who looks pretty and smiles for the fans."

Jem didn't even stop to laugh at that one. "Let's think about how we're going to get back to the Institute without rousing suspicion."

"…They see us coming in together all the time. We're sort of _parabatai_."

Jem sighed, resting his hand on his forehead. "…Don't remind me."

"Ah…apologies," Will said. "That's the kicker, isn't it?"

"Do you regret it?" Jem asked, raising his head to look at Will.

"What?"

"Becoming _parabatai._ "

Will exhaled deeply. "Functionally, now, yes. But no. But yes." He ran his hand through the front of his hair, inadvertently fluffing it up, and looked at Jem in the eye. "Put it this way; when I was fourteen, I made the uncanny assumption that I _wouldn't_ be involved in a homosexual love affair with my best friend."

That comment finally got a deep, shocked laugh from Jem. "Oh, how things change."

"How they do, indeed." Will spent the next few moments looking over Jem's face, going over the little crevices on his cheek and lamenting about how his colourless eyes were nicer to look at than any rainbow. Even although he knew what a rabbit hole they'd dug themselves into, he was damn happy about his choices. When he spoke again, his voice was softer and just loud enough for Jem to hear from where he was sitting. "So- Mr. Thinker. What's your idea about how to get us into the Institute un-ruffled?"

"Well…we can't go in together." Jem's eyes defocused until he was staring absent-mindedly at Will's cheek. "We can go in one at a time. Make sure that time's spread out. You could even ask for me when you get in; whatever you do, make the impression that you have no idea where I was. I'll do the same. We won't arouse suspicion with that- they'll expect us to be worried about each other. As much as it puts a damper on this particular situation, we're still p _arabatai._ "

"I just can't wait for the Angel to smite us in our sleep." Will's eyes narrowed and sparkled as he spoke.

"That's for later," Jem replied. "Right now- Operation Institute." He stood up, brushed the dust off his tunic and reached for his cane resting against the bench leg.

" _Ohh,_ it's an _operation_ now!" Will said gleefully, grinning from ear to ear. Jem let a hand out and Will gladly took it. "I like the sound of that. Do I get a cigar pipe?"

"No, Will."

"-And, by the Angel, _what_ were you thinking by stepping out in the middle of the night without a note! We didn't know where you were! Anything could have happened to you! You had minimal weapons, you were alone- oh, _lords._ " Charlotte rested her beetroot red face on her hand, apparently having talked herself out of steam.

"Will, I have to admit, what you did _was_ a little foolish- what on earth compelled you, again?" Henry asked, his tone changing from a low neutral to a high-pitched, questioning voice.

"I told you," Will said. "There was an emergency."

" _What_ emergency?" Charlotte piped up again, sounding truly grief-stricken.

"It involved a beer can, a mermaid and a whale net…I'll spare you the gory details," he told her, staring down at the ground as if overcome with sadness.

Charlotte pressed her palms against either side of her forehead.

"Whatever in all heavens makes you tick, Will…I'm just glad you're home safe," she said, finally looking up at him with wide, damp eyes.

"I'm glad to _be_ home safe," Will said, with an almost pleading look in his eyes as he looked into Charlotte's.

Charlotte started to blink more, eventually finding her gaze directed at the floor. "Okay. Will, you need to stop doing this. It's not fair on anybody here."

"I swear- _last time._ "

"This was your 10th last time, Will, I need more than-"

Charlotte's sentence was cut off by the tall Institute door swinging open, making a grand racket. Dwarfed by the large doorway, Jem stood, leaning on his cane.

"Oh…Jem!" Charlotte smiled, her cheeks regaining some of the redness. "So glad you're home. Did you get everything you needed done?"

Jem's focus had already latched onto Will. "Yes, it was quite easy…Will?"

"Oh, don't worry, I've already been grilled quite sorely," Will said with a mirthless smile. "I would appreciate it if you would play the devil's advocate here, because it's awfully tiring being a one-man-show all of the time."

"Jem, Will was fine when he came back," Charlotte told him, taking a step towards Jem and clasping her hands around her stomach. "Said he was out all night…er…what what is you said?" She leaned back and craned her neck to look at Will.

"Mermaid. Beer can. So much blood." He kept a grin as he said this, flashing Jem a knowing look.

"Oh…" Jem said, trailing off. He squinted his eyes, pursing his lips together to prevent a smile from escaping. "I'm…sorry about your friend?"

"Wasn't a friend," Will said on the tail of Jem's sentence. "More like a frenemy. A fre-nemesis, if you will." His voice was solid and almost untraceable. Jem had always wondered how he managed to say these things with a straight face.

"Is it anything the Clave should be concerned about?" Charlotte asked.

"…Charlotte," he said on the air of a deep sigh. "I would appreciate if you left my mer-friends out of official business. They can look after themselves."

"I thought you said it wasn't a friend," Henry, who Jem had to admit he hadn't noticed yet, piped up.

"Oh, no, _that_ wasn't a friend," Will said with raised eyebrows. "No. That was one of the nasty ones…good riddance, I say."

"Well…" Charlotte said, her wide eyes trailing to the side of Will. "A-As long as there was an endangerment of life, I think we can excuse it."

"Oh, there was an endangerment of life," Will said. "A huge, turquoise, three headed-"

Jem strided towards Will, gripping his shirt by the shoulder and pulling him along with him as he started down the corridor. "I'll take him off your hands now, if that's alright."

"Play nice!" Charlotte called after them as they disappeared around the corner.

Will reached up to his shoulder, and took Jem's hand off. He interlaced his fingers through Jem's, causing Jem's face to drain of colour and redden at the same time, somehow. He halted immediately.

"Will- not here," he whispered harshly.

"Nobody's looking," Will said. "I doubt they can even hear us." He turned his body so that their joined hand was the only thing separating them, and looked Jem in the eye. Jem let out a puff of air, realising that he could never get mad at those eyes, at least not indefinitely. _This is going to complicate things._

Jem smiled warmly. "Okay, Romeo- we've got work to do." He gently pulled his fingers out from between Will's, and continued walking. Will kept still for a half-beat, but eventually caught up.

"Where are we going, exactly?" Will asked.

"To see about the whole, 'Angel smiting us down from the Heavens' thing."

"Ah."

"The only thing I can find here is something about angels and jealousy, but the way it's translated, it could either be sacred knowledge or Edgar Allen Poe." Jem stood up with a hefty book he'd been quietly skimming over for the last few minutes. He set it down on the nearest table and pulled out a chair to sit down.

"What's the difference?" Will lay horizontally on a cushioned bench nearby where Jem was sitting. The palms of his hands rested on his taut stomach, and he was staring at the ceiling, absent-mindedly trying to figure out the pattern. The front of his hair, afflicted by gravity, fell down over his face. Every once in a while he'd have to blow it out of his eyes. "If Edgar Allen Poe wrote the Bible, I would actually read it."

Jem looked up from the tome, now spread out on the table. "You know, you could actually help."

Will lifted his head as much as he could with the position he was in. "What part of 'pretty face' don't you get?"

Jem scoffed light-heartedly, standing up and pushing his chair from under him. He strided over to the bench and took a seat on the arm, just above where Will's feet were. He still wore the boots he'd put himself in before going to Limehouse.

"It looks like there's not really a reason _why_ parabatai are forbidden to, well, you know. It seems they just _are._ " Jem shrugged microscopically. He knew himself how tedious the residents of Heaven could be- so much so that he found himself searching for a purpose for all of this research- but he also knew that angels didn't care whether their whims were tedious. They would probably destroy the man that made off with the bread that they were about to make toast with, and Jem didn't want to, by any stretch of the imagination, underestimate their wrath.

"I can tell you why," Will said, pulling himself up until he was almost sitting. His eyes were indignant and filled with a subtle kind of smugness. "Because Shadowhunters would slip, make mistakes if they were all goo-ey eyed for their _parabatai._ "

"Well…I like to think I've done okay so far," Jem said softly, a hint of a smile on his face.

Will's eyes lit up and widened, a dopey grin painted on his face. He flopped onto his back again. Shoving his hands over his mouth as if he'd said something unthinkable, he let out a muffled, high-pitched groan.

"What?" Jem asked, snapping into action. He leaned forward over the arm of the bench until he was hanging over Will's chest. He thanked the Angel that he was lanky, and that the Institute hadn't bothered to invest in longer benches.

Will took his hands from his mouth, his eyes still looking like something very sharp had been inserted into his ass very suddenly.

"You're just so cute! I don't know whether to squeeze you until you beg me to stop, or- or swordfight you until I feel manly again," he blurted out.

Jem laughed, so deeply and so intensely that it was barely more than vibrations. His eyes squeezed shut to get rid of the water that had formed in the corner of them. He pulled himself back to the arm of the bench.

"Oh, Will." When he had calmed down a little, he wiped the droplet still left in his left eye with his sleeve. "We can do swordfights if you like."

"Oh, I like." He winked.

Jem went into another laughing fit, this time buckling over the edge of the arm. Will watched him intently as his face reddened and his cheeks became damp.

"Hey. Hey, Jem?" Will asked, half to rouse him.

"Yeah?" Jem replied, slowly opening his eyes and straightening his back.

"This is really fun."

Jem's eyes narrowed, an inquisitive half-smirk on his face. "Er…good? I'm having fun too."

"We should do it again," Will said. "In fact…" He looked around slowly before locking eyes with Jem again. "This place would be a prime location to have our operation base."

"Operation base?"

"You know…this thing is like a secret mission. Espionage. Like…Operation _Parabatai._ We're going to need a place where we can…meet in private."

"It's not entirely private," Jem pointed out. "Anybody can stroll in at any time- I believe Henry's been spending a lot of time lately, because of you-know-what."

"That's true. But you know when there _isn't_ usually anybody here?"

"When?"

"Midnight." Will's voice had gone soft and quiet. He was tracing Jem's face the way he would the pattern on the ceiling, or the swirls of oak on the tree. A subdued grin came over his face, that of a man so intrigued in what he was looking at that he forgot to tighten his jaw. "Then I'll literally be Romeo."

Jem chuckled lightly. "I don't think _Romeo and Juliet_ is something we should be trying to emulate, for one that would make me a 13 year old girl and for two, they both end up dying in the end."

Will pursed his lips together. "Romeo and Mercutio?"

"That would mean you die," Jem said. "And Mercutio and Romeo weren't even together."

"Fine- Mercutio and Romeo in another universe where Juliet doesn't exist," Will said. "And don't even fight me on this- Mercutio and Romeo were _so_ gay for each other."

"Oh, I think Juliet does exist in this universe," Jem said. "But she's not here right now. So she doesn't matter."

Will fell silent for a few minutes, still surveying Jem's face like he was an abstract sculpture that Will was still trying to find the meaning of. "I love how you didn't argue about Romeo and Mercutio being in love with each other."

"I know better than to get in the way of you and your literature," Jem said with a faint smile that drooped on one side.

"Then this is going to work out _just_ fine." He pulled himself into a sitting position and then up on his feet. "Come on. The angels will wait for another day."

"Where are we going?"

"Well…you did promise me a swordfight," Will said, grinning widely.

Jem brought his hand to his face, letting out a laugh that sounded more like an exhale of air.

"I'm not even going to ask."


End file.
